Note 5 - Derivative and Other Hedging Instruments - Schedule of Derivative Instruments Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Losses on derivative and other hedging instruments	$ (8,772)	$ (140,825)	$ (136,717)	$ (26,858)
Treasury Note Future [Member] | Short [Member]
Losses on derivative and other hedging instruments	(3,159)	(14,668)	(26,789)	16,100
Interest Rate Swap [Member]
Losses on derivative and other hedging instruments	(2,298)	(110,085)	(102,549)	(39,469)
Payer Swaptions [Member] | Short [Member]
Losses on derivative and other hedging instruments	0	0	0	(72)
Dual Digital Option [Member]
Losses on derivative and other hedging instruments	0	(105)	0	(500)
TBA Contracts [Member] | Short [Member]
Losses on derivative and other hedging instruments	(4,272)	(16,315)	(8,908)	(3,370)
TBA Contracts [Member] | Long [Member]
Losses on derivative and other hedging instruments	$ 957	$ 348	$ 1,529	$ 453